Brazing flux



 

2. A BRAZING FLUX THAT IS RELATIVELY NON-TOXIC TO THE USER CONSISTING OF OXYGEN CONTAINING COMPOUNDS OF BORON, SODIUM, POTASSIUM AND LITHIUM IN PREDETERMINED PROPORTIONS AND VIOLATILE MATERIAL SO THAT WHEN SUBJECTED TO FUSION AT BRAZING TEMPERATURE THERE IS PRODUCED A LOW VISCOSITY FLUID FLUX COMPOSED OF FROM 60% TO 70% BY WEIGHT OF BORON OXIDE, FROM 1/2 OF 1% TO 10% BY WEIGHT OF LITHIUM OXIDE AND THE BALANCE BEING AT LEAST 10.2% AND NOT IN EXCESS OF 23% BY WEIGHT OF SODIUM OXIDE AND AT LEAST 7% BUT NOT EXCEEDING 35% BY WEIGHT OF POTASSIUM OXIDE. 